One of the main problems with the “theory” of anthropogenic global warming is its reliance on rising atmospheric CO2 levels to force a global rise in temperature. This is predicted by climate change proponents by running large, complex computer models that imperfectly simulate the physics of Earths biosphere: ocean, land and atmosphere. Central to tuning these general circulation models (GCM) is a parameter called climate sensitivity, a value that purports to capture in a single number the response of global climate to a doubling of atmospheric carbon dioxide. But it has long been known that the Earth system is constantly changing—interactions shifting and factors waxing and waning—so how can a simple linear approximation capture the response of nature? The answer is, it can not, as a new perspective article in the journal Science reports.

Most people fall into one of two categories when it comes to predictions of future climate calamities: they either do not realize that the predictions are predicated on computer models or they unquestionably trust the models to reveal the future. A clear and lucid online article in Nature Geoscience addresses the current state and limitations of climate modeling. The article points out that State-of-the-art climate models are largely untested against actual occurrences of abrupt change. “It is a huge leap of faith to assume that simulations of the coming century with these models will provide reliable warning of sudden, catastrophic events,” the author states. To counter claims of predicted “tipping points,” incidents of abrupt climate change from the past are examined—incidents that current models get wrong.

Methane is an important greenhouse gas, 30 times more potent than CO2, but our knowledge of the methane cycle is woefully inadequate. Sediments on the ocean's floor contain immense quantities of methane and there are enormous fluxes of methane into and out of these sediments. Trapped frozen in ice, there are some 10,000 gigatons of carbon stored under the sea—twice as much carbon as contained in conventional fossil fuel reserves. Some scientists consider the release of this methane the single worst environmental danger we face as a species. A massive release of ocean floor methane could cause real runaway global warming that would have dramatic impact on life. But methane continually leaks from seabeds around the world, contributing to the total amount of carbon injected into the ecosystem. A new report finds that ocean methane concentrations have been underestimated by a factor of 10 to 20 fold.

International negotiators at a recent UN climate conference held in Bangkok repeated the demand that global warming this century be limited to no more than 2˚C. But while those attending the UN boondoggle stuck to the climate alarmist party line, results from a newly published Canadian government climate study concluded that “it is unlikely that warming can be limited to the 2˚C target.” The modeling based paper found that reaching the stated IPCC goal would require that greenhouse emissions “ramp down to zero immediately,” which means shutting down the global economy and banning the automobile. Moreover, starting in 2050 scientists would need to actively remove greenhouse gases from the atmosphere, requiring a rush to implement controversial and possibly dangerous geoengineering programs. Why does the global warming lobby continue demanding the impossible? Perhaps it is because global warming isn't about climate change at all.

It is well known that water, H2O, is the single most important greenhouse gas. But water also plays a central role in determining the delicate balance of energy and mass that regulates the temperature of Earth. A wide range of predictions have been made regarding water in a warming climate, ranging from catastrophic droughts to increased monsoon rains and tropical storms. Conventional wisdom states that a warmer world is a wetter world. In a newly published paper in the journal Science, two researchers examine the Eocene (∼56 to 34 million years ago), looking for clues to the tropical climate–water relationship. Annual global temperatures during the Early Eocene Climatic Optimum (EECO) around 50 million years ago were as much as 12°C higher than modern values. The new results provide compelling evidence that the tropical engine of the water cycle was more active than predicted by current climate models.

Climate alarmists have been slow to learn that their over-reliance on computer models and unproven theories has harmed their public credibility. In an attempt to counter the richly deserved bad press that climate science has been garnering these days, a number of global warming true believers are trying a different, more fact based approach to scaring the public. One such attempt recently appeared in the journal Science—not as a paper describing original research but as a perspective article. In it, a Senior Scientist at the National Center for Atmospheric Research, in Boulder, Colorado, attempts to “weave together” some carefully selected “threads in the discussion of climate” to arrive at a very familiar and unconvincing conclusion.

Scientists believe that carbon released from the ocean floor played a key role in past episodes of climate change. Around 55 million years ago, the break-up of the northeast Atlantic continents was associated with the injection of large amounts of molten magma into seafloor sediments. Formation of the North Atlantic basalts heated the carbon-rich sediments, triggering the release of large quantities of methane and carbon dioxide into the ocean and atmosphere. It has been suggested that this release of previously sequestered carbon was responsible for a 100,000 year period of rapid temperature rise known as the Paleocene-Eocene Thermal Maximum or PETM. Three letters published in Nature Geoscience suggest that carbon trapped beneath the seabed continues to influence carbon dynamics, at least in the deep ocean.

Time after time, the public has been harangued by climate change “experts” predicting all form of devastation due to anthropogenic global warming. The Greenland and Antarctic glaciers will melt, as will the sea ice covering the Arctic Ocean. Temperatures will rise by 2-6°C, perhaps more in higher latitudes. Weather patterns will shift, there will be droughts and torrential monsoon rains, cyclones will increase in intensity—where will it all end? Here's a thought, we might find the world a nicer place after a bit of global warming. In fact, given the general cooling trend seen over the Holocene (the period since the last glacial period ended around 14,000 years ago) and the Cenozoic (the time since the dinosaurs died, around 65 million years ago) human CO2 may be, in some small way, the only thing delaying another devastating ice age.

Much has be written and even more said about stopping climate change. The total foolishness of such a quest is obvious to anyone with even the most cursory understanding of Earth's climate over the Past 65 million years. The more science learns about the ever changing nature of climate the more capricious nature appears and the less significant the labors of H. sapiens are revealed to be. To place the ludicrous arguments and unsubstantiated fears of climate catastrophists in perspective, it is instructive to survey Earth's climate since the demise of the dinosaurs—the geological time period called the Cenozoic Era. During this long span of time, Earth's climate has undergone a significant and complex evolution. If one truth has been discovered by human science it is that Earth's climate is always changing, driven, as one set of researchers put it, by trends, rhythms and aberrations—the mechanisms of climate change.

Though Earth and its climate are billions of years old, climate science is still very young. So young that surprising new discoveries are constantly being made. One such discovery in the field of paleoclimatology—the study of Earth's climate in the distant past—was the uncovering of a period of great warming around 40 million years ago, in the middle of the Eocene Epoch. In the midst of a general cooling trend beginning at the end of the preceding Paleocene Epoch (~55 mya) there were a number of dramatic, sudden bursts of global warming. The most celebrate of these is the Paleocene-Eocene Thermal Maximum or PETM, when surface temperatures rose by 5-7°C. Recently, science has discovered another hot interval 15 million years later during the Middle Eocene. Named the Middle Eocene Climatic Optimum (MECO), it marked a time when deep sea temperatures rose about 4-5°C and atmospheric CO2 levels peaked. As new information is uncovered, climate scientists are scrambling to interpret what caused this second, more sustained period of warming and what it may mean for current climate conditions.

One of the scary predictions made about the impact of global warming is the extinction of many current species leading to a crisis in biological diversity. Like most of the speculative effects of global warming, this prediction is not only without scientific basis, it is precisely backward. A new paper in the journal Science, studying the impact of rapid global warming at the Paleocene-Eocene boundary, show that rapid tropical forest diversification occurred without plant extinction. Moreover, diversity seemed to increase at higher temperatures, contradicting previous assumptions that tropical flora will succumb if temperatures become excessive. The tropical rainforest was able to flourish under elevated temperatures and high levels of atmospheric carbon dioxide, in contrast to speculation that tropical ecosystems were severely harmed by the heat.

Climate scientists continue to be fascinated with the Paleocene–Eocene Thermal Maximum (PETM), which took place about 55 Myr ago. This period of sudden global warming and increasing atmospheric CO2 represents a possible model our present era of warming climate and growing CO2 emissions. Studying the PETM, therefore, may provide insight into climate system sensitivity and feedbacks. Just such a study, reported in Nature Geoscience, found that CO2 forcing alone was insufficient to explain the PETM warming. Scientists speculate that other processes and/or feedbacks, hitherto unknown, must have caused a substantial portion of the warming during the Paleocene–Eocene Thermal Maximum. Simply put, CO2 did not cause the PETM climate change.

Throughout Earth’s history, there is evidence of large carbon dioxide releases, greenhouse conditions, ocean acidification, and major changes in marine life. About 120 million years ago (mya), during the early part of the Cretaceous period, a series of massive volcanic eruptions pumped huge amounts of carbon dioxide into Earth's atmosphere. During the Aptian Oceanic Anoxic Event, atmospheric CO2 content rose to about twice today's level. Eventually, the oceans absorbed much of that CO2, which significantly increased the water's acidity. The change reduced the amount of calcium carbonate (CaCO3) in the water, making it difficult for creatures such as some kinds of plankton to form shells. But the plankton did not die out. In fact, the geological record indicates that ocean biota can adapt to CO2 concentrations as high as 2000 to 3000 ppm—five to eight times current levels.

The Appalachian mountains are seldom mentioned among the world's great mountain ranges. Consisting mostly of low gentle ridges, when compared with the snow-capped peaks of the Himalaya, Andes, or Alps many would hesitate to call them mountains at all. But they are a large and ancient range, stretching over 1500 miles along the eastern portion of North America. The time of their formation has been dated back to the Paleozoic, with major uprisings occurring 650 million years ago. Then, about 460 million years ago, during the Ordovician period, they were the site of one of the most violent volcanic outbursts in Earth's history. New research reveals that, following that bout of vulcanism, weathering of Appalachian rock may have triggered one of Earth's major ice ages—a relatively brief frigid period that ultimately killed two-thirds of all species on the planet.

We have all heard the litany of woes about to befall mankind due to global warming: failing crops, spreading deserts, increased storm activity, rampant disease, and so forth. But these are not the most frightening side effects of global warming. Indeed, the IPCC's list only scratches the surface of the prophecies of doom and despair. Among the predicted results of a warming climate are smaller livestock, an increase in kidney stones, more frequent bear attacks and a host of other maladies and misfortunes.